In this episode, we return to the Roman fort of Branodunum on the Norfolk coast to take on an ambitious challenge. Without a single trench being opened, John Gater, Jimmy Adcock and the geophysics teams set out to map the entire site using the latest technology, surveying hectares of landscape to reveal what still lies hidden beneath the surface. What emerges is extraordinary but as the picture builds, so does the complexity, and the team are faced with a familiar question: how do you interpret a site you can’t yet see? This is a slightly different kind of Time Team story - one that focuses on the process, the technology and the decisions that shape what comes next.